Hydraulic pump



July 19, 1960 w. R. LEISSNER HYDRAULIC PUMP Filed Sept. 23, 1957 2 Sheets-Sheet 1 INVENTOR.

A 7' rams 57s.

y 1950 V w. R. LEISSNER Q 4 HYDRAULIC PUMP Filed Sept. 23, 1957 2 Sheets-Sheet 2 INVENTOR.

ATTORNEYS.

2,945,444 HYDRAULIC PUMP William RQLeissuer, Milwaukee, Wis., assignor to Dynex, Inc., Pewaukee, Wis, a corporation of Wisconsin Filed Sept. 23, 1957, Ser. N 0. 685,441

12 Claims. (Cl. 103-2) This invention relates generally to hydraulic pumps and finds particular utility in such pumps of the multiple piston type.

In conventional pumps of this general character, when the pistons or cylinders become scored, worn or otherwise defective, it is usually necessary to replace the en tire cylinder barrel. This, of course, is costly, but also requires considerable down time of the hydraulic system because of the necessity of removing the entire pump or barrel from its mounting and associated connections.

When a different capacity pump is required in conventional installations, it is usually necessary to replace the entire pump with one of the desired capacity. This interchange of pumps requires a considerable amount of time for reasons above mentioned and furthermore requires a large number of complete pumps to be stocked and kept readily available.

It is an object of the present invention to provide a hydraulic pump which is highly flexible as to the various combinations of installations in which it may be used and which obviates the above-noted shortcomings of prior art devices.

In accordance with this invention a hydraulic pump is provided which has removable cartridges containing the pumping piston and its individual cylinder, which cartridges can be quickly and easily removed and replaced when any pant thereof is defective. It is therefore necessary to replace only the defective part instead of a substantial portion of the pump.

The invention also contemplates that these cartridges may be of different capacities so that the displacement of the entire pump may be readily varied. In other words, any number of these cartridges may be replaced with cartridges of different capacities so any desired volume may be obtained without changing the drive speed of the pump.

The invention further provides that these cartridges may be replaced by isolating flow cartridges. These isolating flow cartridges can be made from the same tooling employed for the manufacture of other cartridges, and the substitution made in the pump without any modification to the pump. These isolating cartridges may also be of different capacities so that various volumetric flows may be directed to separate points of utilization.

In a pump of this type, the frequency of cyclic operation between the inlet and outlet check valves is very critical and any axial shifting of the pumping cylinder relative to the piston destroys this desired frequency.

It is therefore an object of this invention to provide a novel means for fixedly positioning the cartridge containing the pumping chamber or cylinder.

Another and important object of this invention is to provide an inlet check valve spacer of such construction and shape that the inlet flow pattern through the piston is greatly improved and turbulence therein substantially reduced. The result is a particularly efficient pumping unit. This aspect of the invention also provides a novel Patented July 39, 1960 means for assembling the spacer in a fixed and predetermined correct axial position.

These and other objects and advantages will appear hereinafter as this disclosure progresses, reference being had to the accompanying drawings, in which:

Figure 1 is an axial cross-sectional view through a hydraulic pump embodying the features of this invention,

Figure 2 is a transverse cross-sectional view taken on line 2-2 of Figure 1, through the discharge manifold,

Figure 3 is a transverse cross-sectional view taken on line 3-3 of Figure 1, and showing the inlet valve spacers in the discharge end of the pumping pistons,

Figure 4 is an enlarged fragmentary cross-sectional view of an isolating cartridge and a plug having a port connection, inserted in the pump instead of the cartridge and plug shown in the other figures,

Figure 5 is an axial cross-sectional view, on an enlarged scale, through an inlet check valve spacer shown in Figures 1-3 made in accordance with this invention and showing the flow pattern therethrough, Figure 6 is another view, similarly enlarged, of th spacer shown in Figure 5, and

Figure 7 is a still further enlarged end view of the spacer shown in Figures 5 and 6, and taken generally from line '7--7 of Figure 6.

Referring more particularly to the drawings, the pump housing comprises a cylinder barrel section 10 secured by circumferentially spaced cap bolts 11 to a drive section 12 and having an O-Iing seal 13 therebetween. A chamber 14 is defined within the housing into which a supply of fluid is introduced through the inlet port 15.

A drive shaft 16 extends through the housing and is suitably journalled in anti-friction bearings 17 in section 12 and its end is piloted in the anti-friction bearings 18 located in the barrel section 10. A shafit seal 19 prevents leakage of fluid from the housing.

A wobble plate '20 is secured to the drive shaft by a key 21 and has an eccentric surface 22. An axial thrust bearing plate 23 is located in chamber 14 and a thrust ring 24 having a plurality of anti-friction bearings 25 therein is located between the bearing plate and the wob ble plate.

An anti-friction ring member 27 is mounted on an eccentric portion 28 of the drive shaft 16 and is adapted to rotatably bear against the eccentric surface 22. A hardened steel plate 29 is also mounted on eccentric portion 28 for rotation in respect thereto.

The cylinder barrel section 10 of the pump housing has a plurality of circumferentially spaced bores 30 extending therethrough which are arranged in parallelism and in an axial direction. These bores are all connected together by a common manifold 31 which places them in communication with the common discharge port 32 (Figure 2).

A replaceable cartridge assembly 35 is inserted in each bore 359 and accurately secured therein against either axial or rotational displacement as follows. The sleeve 36 of the cartridge has a recess 37 in its periphery which is adapted to snugly receive the dowel portion 38 of the cap screw 39. A seal 40 prevents any fluid leakage to the outside of the pump. The screw 39 accurately positions the sleeve in an axial correct predetermined position and also prevents any rotational movement of the sleeve. A plug 41 has a portion 42 which threadably engages the end of sleeve 36. When the plug is tightened, its collar portion 43 bears against the outside of the pump housing and because of the clearance between the collar 43 and the sleeve, draws the sleeve to the right, as viewed in Figure 1Q As a result the sleeve is drawn up tight against the locking dowel 38, thus securing the sleeve in position. An O-ring seal 44 seated on the portion 45 of the plug acts to seal against fluid leakage. An-

other O-ring seal 46 is located between the sleeve 36 and its bore 30 to prevent fluid leakage therebetween. To remove the entire cartridge assembly it is only necessag-y to withdraw the dowel portion 38'.

The cartridge assembly also includes: a cylinder 47 in the. sleeve 36 which. forms, a pumping chamber for the pistodassenrbly 48 reciprocatingly mounted therein. The

cylinder 47, of; the cartridge assembly shown in Figures 1 and 2-, is placed; in fluid communication with the manifoldj passage 31 by means, oi the crossbore 50 in the sleeve; 36..

12 Outlet check valve is provided; for each pumping unit and includes a check ball. 52 which, is. adapted to seat: again t. the; ring, seat 53; located in the counterbore 54 of the sleeve. The. seat: 53. is held. against axial, displacementbythe locking ring 55 which. is threadably engaged in. the. sleeue. A spring 56 bears. against the ball vie-ldingly hold: it against. its. seat and also bears against the inner end. of, plug: 41., A projection 57 is formed integrallyon; the inner end of the; plug and acts as a logatingi guide for the: spring; 56; surrounding, it.

Thepistou assembly; 48. may also be. considered as part of the cartridge assembly: and includes thepiston 58 which has; alhemi-spherical end: 5.9,. on. which is held captive by snap ring 60, a universally tiltable: slipper 61: The slip-- Pit are urged; firmly: against the, wobble plate assembly by: thespring62 which acts between. the shoulder 63 of the sleeve and the collar 64, which is secured tothe piston. by: snap. ring 65.

viewed. in: Figure; 1,, the piston 58 has av series of burns; 67 6.8,. 69: and 70 which. progressively decrease uidim eter in, that: order and. which are allconnected together; A. pair of;cross' ports; 71, place the pump inlet chamber 141 in. fluid communication: with bore 7.0..

A111 inlet; check. valve. is; provided within each piston which serves. toadmit fluid. to-the pumping chamber: 47 when; the; pistonis. moved -to;.the left (Figure 1-) during its suction. stroke... When the piston delivers its. pumping stroke the inlet valve, is closed; Thisinlet valve com- P,I'i$5.,3ihk'b3l1 72pwhiclr sealingly'seats against the shoulder-J5 formedibyrthejuncture ofnbores 68.and 69.

A. spring 7.4; urgesethe ball to. this. seated position. The sprin talsozbearsagainst the inlet valve spacer 75 which is,= fixedly and accurately positionedin-borez67 within the limits predetermined by the snap ring 76 and theshoul derv formedrbyz the junction. of; bores. 67:. and 68. The exactnaxial locatiomofithesnap ring 7'6; relatively-to the hall 72';is;predetenninedvand:it isaneasy matterto' assembie-athisgpiston;without-"error. In'other words, it is-iunnecessary to first sorem theespacer into contact. with. the ball filld'ithfill'lhH-Ck'itflfi? redeterminedtnumbero-f' revolutionsewherezittwould :be; lockedin-place.

The; spacer; 75:: thus... accurately. locatest the maximum travel-.ofithe. check ballin the opening. direction. The

extentcf this. ball movement isimportant as the frequency oifcyclicoperation.between:the-inlet ball 72 andthe outlet ball 52 is critical to the proper high speedoperation ofltheseepistons andthesmooth flow of fluid therehtought;

The spacer-made in accordance with this: invention is suchishape; and construction that a..highly improved flQWtPattern ofgfluid therethrough has been achieved. The flpvw throughithis -'particular.location:must be without turbplencegifzmaximumaefl'iciency of the pumping-unit is to ee btained.

Referring;to:Figures.=5;v 6;.and:7,- the-spacer 75- includes a; tubu1a L1portionJ7 which. .has integrallys-formedat its leading edge sth'e flat, centrally-.- located,. ball contacting stam na; ThLStII11 isofsmallendiameter andwidth. than the internal, bore;79,.of; thel stem.;portion:.78. The stem- 7;8g is cut, away"at;its.;centraln part adjacent .the. tubular pgrti ta formsan opening 80.whichcontri-butes to the srnpoth flow ofiffluid. through'.. the..spacer.;. Asshown in Figured, ;a.: substantially .semircircular opening 81. is pro-: vided .ah either side of.:the-:spacerthroughiwhich:thetfluid- 4 flows. By splitting the flow with the openings of this shape, a diametrically opposed flow has been obtained which has no turbulence. The result has been a marked increase in the efliciency of these pumping units.

When it is desired to use one of these pumps to supply separate hydraulic mechanisms with independent lines of pressure fluid, any number of cartridges shown in Figure 1 may be replaced by an isolating cartridge shown in Figure 4. As well as embodying all the advantageous features as to replaceability and serviceability of the cartridges of Figure 1', this isolating, cartridge candirect the flow of a particular pumping piston. to a separate source of utilization. In Figure 4, parts identical to corresponding parts in Figure 1 have been similarly numbered. In this isolating cartridge, the sleeve 36a is similar to sleeve 36 except the cross bores 50 are not present. Thus the sleeve 36a blocks flow of fluid from the pumping cylinder 47 to' the manifold passage 31. Instead the fluid is directed through. a series of .cir'cumferentially spaced cross ports 83 which extend into the axial bore 84 in the plug: 411;. The. outer end of bore 84: has a threaded portion 85 which is adapted to receive a conduit (not shown)- for' conducting: pressure fluid to: a source of utilization which is separate from that with which port 32 iscon nected. Itwill be appreciated that the cartridges of'Figures 1 and 4 can. be made from substantially the same toolage.

Any number of isolating cartridges can be used depending on the'number of'separat'e mechanisms that require individual. sources of pressure fluid. Either type of eartridgecan be readily serviced or replaced when worn or replaced. with a cartridgeof. different pumping; capacity; Thus a highly versatile and efficient pumping unit has been provided. 7

Various modes of carrying out the inventions are contemplated as. beingwithin the scope of the following claims particularlypointing out. and distinctly claiming the subject matterv which; is' regarded as the invention;

I claim:

1. A piston type hydraulicipump comprising; ahousing having a discharge port, a quick removable cartridge assembly secured in said housing. removable locking means inv said housing for locating. and securing said cartridge in said housing; said cartridge assembly com= prising, a sleeve having a cylinder therein, a fluid'passage way placing said cylinder in communication with said dis' charge port, an outlet checkvalve withinsaid sleeve and located between said cylinder" and saidpassageway, a piston reciprocally" mounted within said cylinder for pumping fluid through said outlet check 'valve', and. an adjustable means'between said sleeve and said housing and threadably engaging said sleeve wherebysaid" sleeve may be brought into firm engagement with said locking means; said" cartridge assembly adapted to be retnoved from said housingas acomplete-unitby-only disengaging said locking-means from said" assembly.

2. A piston type hydraulic'pump comprising; ahousing having inlet and outlet ports, aquick removable cartridge assembly secured in said housing, removable locking means in said housing for locatingand securing said cartridgeaxially in said' housing; said cartridge assembly comprising, asleeve having a cylinder therein and-also having a fluid passageway-placingsaid'cylinder'in' conimunication with said outlet port, an outlet check valve within said sleeve and locatedbetweensaid cylinderand said passageway; a'pis-ton reciprocally mounted within said cylinder and adapted to-place said housing inlet-port in fluid communication with said' cylinder; and an adjustable means betweensaid sleeve and" said housingand threadably engaging said sleeve whereby said sleeve "may be-brought into firm engagement with said locking-means; said cartridgeassembly adapted to'beremoved from said housing; as a complete unit by only disengagi'ng said locking means from: said* assembly;

3. A piston type hydraulic pump comprising, a housing having inlet and outlet ports, a quick removable cartridge assembly secured in said housing, movable locking means in said housing for engaging said cartridge and locating and securing said cartridge in a definite axial position in said housing; said cartridge assembly comprising, a sleeve having a cylinder therein and also having a fluid passageway placing said cylinder in communication with said outlet port, an outlet check valve within said sleeve and located between said cylinder and said passageway, a piston reciprocally mounted within said cylinder and adapted to place said housing inlet port in fluid communication with said cylinder, and an adjustable plug threadably engaged in said sleeve and adapted to bear against said housing whereby said sleeve may be drawn tightly against said locking means; said cartridge assembly adapted to be removed from said housing as a complete unit when said locking means is shifted out of engagement with said assembly.

4. A multiple piston hydraulic pump having a housing and a plurality of pumping assemblies in said housing and adapted to discharge through a common outlet, comprising, shiftable locking means in said housing for locating and securing each of said assemblies in said housing; each assembly comprising, a sleeve having a cylinder therein and also having a fluid passageway placing said cylinder in communication with said outlet, an outlet check valve within said sleeve and located between said cylinder and said passageway, a piston reciprocally mounted within said cylinder, and an adjustable means threadably engaging said sleeve and abutting against said housing whereby said sleeve may be tightly drawn up against said locking means; said assemblies each adapted to be removed from said housing as a complete unit when said locking means is disengaged from said assembly.

5. A hydraulic pump comprising housing means having a plurality of substantially axially positioned and circumferentially spaced bores therein, a common outlet port in said housing, a discharge manifold placing said bores in fluid communication with said outlet port, a quick removable cartridge assembly in each of said bores, shiftable locking means in said housing for accurately locating and removably securing said cartridge assemblies in said bores, said assemblies comprising, a sleeve having a cylinder therein, a fluid passageway placing said cylinder in communication with said manifold, an outlet check valve within said sleeve and between said cylinder and said passageway, a piston reciprocatingly mounted within said cylinder, and an adjustable plug threadably engaging said sleeve and bearing against said housing whereby said sleeve may be drawn up tightly against said locking means; each said cartridge assembly adapted to be removed from said housing as a complete unit when its corresponding locking means is shifted therefrom.

6. A hydraulic pump comprising housing means having a plurality of substantially axially positioned and circumferentially spaced bores therein, a common outlet port in said housing, a discharge manifold placing said bores in fluid communication with said outlet port, a quick removable cartridge assembly in some of said bores, shiftable locking means in said housing for accurately locating and removably securing said cartridge assemblies in said bores, said assemblies comprising, a sleeve having a cylinder therein, a fluid passageway placing said cylinder in communication with said manifold, an outlet check valve within said sleeve and between said cylinder and said passageway, a piston reciprocatingly mounted within said cylinder, and an adjustable plug engaging said sleeve and said housing whereby said sleeve may be drawn up tightly against said locking means; each said cartridge assembly adapted to be removed from said housing as a complete unit when its corresponding locking means is shifted therefrom, an isolating cartridge assembly in at least one of said bores comprising an imperforate sleeve having a cylinder therein, second locking means to locate and detachably secure said isolating assembly in said bore, said imperforate sleeve isolating its cylinder from said manifold, a removable discharge plug threadably engaged in said imperforate sleeve and bearing against said housing to draw said imperforate sleeve tightly against said second locking means, said discharge plug having connecting means to receive a conduit and also having a passage extending therethrough, and an outlet check valve between said imperforate sleeve cylinder and said passage.

7. A multiple piston hydraulic pump having a housing defining a plurality of circumferentially spaced bores connected to a common discharge passage, a quick replaceable cartridge assembly comprising, a sleeve adapted to be accurately and securely positioned in one of said bores and having a cylinder therein, said sleeve adapted to be inserted in said bore of said housing from the outside of the latter, means between said sleeve and said housing for axially securing the sleeve in said housing, said sleeve also having a bore adapted to place said cylinder in fluid communication with said passage, a pumping piston in said cylinder, an adjustable plug threadably engaging said sleeve and adapted to abut against said housing whereby said sleeve can be moved axially by adjustment of said plug and an outlet check valve in said sleeve between said cylinder and said bore whereby fluid pumped by said piston is discharged into said passage.

8. A multiple piston hydraulic pump having a housing defining a plurality of circumferentially spaced bores connected to a common discharge passage, a pumping cartridge assembly comprising, a sleeve adapted to be accurately and securely positioned in one of said bores and having a cylinder therein and also having a bore placing said cylinder in communication with said passage, said sleeve adapted to be inserted in said bore of said housing from the outside of the latter, means between said sleeve and said housing for axially securing the sleeve in said housing, a pumping piston in said cylinder, a spring mounted on said sleeve and acting against said piston to urge it in a suction direction, an adjustable plug threadably engaging said sleeve and adapted to abut against said housing whereby said sleeve can be moved axially by adjustment of said plug, and an outlet check valve in said sleeve between said cylinder and said bore whereby fluid pumped by said piston is directed into said passage.

9. A multiple piston hydraulic pump having a housing defining a plurality of circumferentially spaced bores connected to a common discharge passage, an isolating cartridge assembly comprising, a sleeve adapted to be accurately and securely positioned in one of said bores and having a cylinder therein and having means thereon adapted to be engaged by means on said housing for securing said sleeve against axial movement in said hOUSr ing, that portion of said sleeve located in said bore being solid to thereby block flow from its piston to said common discharge passage, a pumping piston in said cylinder, a plug threadably engaging said sleeve and adapted to abut against said housing, said plug having means for connection to a conduit and also having a passage extending therethrough, and an outlet check valve in said sleeve between said cylinder and said passage whereby fluid pumped by said piston is diverted from said common discharge passage by said sleeve and discharged through said passage in said plug.

10. A hydraulic pump comprising housing means having a plurality of spaced bores therein, a common outlet port in said housing and communicable with said bores, a quick removable cartridge assembly in at least one of said bores, shift-able locking means in said housing for accurately locating and removably securing said cartridge assembly in said bore, said assembly comprising, a sleeve having a cylinder therein, a fluid passageway placing said cylinder in communication with said outlet port, an outlet check valve within said sleeve and between said cylin de'rf'and saidpassageway, apiston re'ciprocatin I mounted within said cylinder, and an adiustable ping ginfg sleeve and said housing whereby'said" sleeve", nay be drawn up tightly against said locking means; saidcartridge assembly adapted to be removed from said housing a complete unit when its locking means is shifted therefrom, an isolating cartridge assembly at least one of said bores comprising an iriiperfoi ate sleeve having a cylinder therein, second locking meansioilo cate and detachably secure said isolating asseriicilyin said bore, said imperforate sleeve isolating its cylinder from said outlet port,- a removable discharge plug thre'adably engaged in said imperforate sleeve and bearing against said housing to draw said imperforate sleeve tightly against said second lock-ing means, said discharge plug having apass'ag'e extending therethrough, and an outlet check valve in said isolating cartridge;

11. An isolating cartridge assembly for a multiple piston hydraulic pump of the type having a housing defining a plurality of circumferentially spaced bores don'- nected to a common discharge passage, said assembly comprising, an imperforate sleeve adapted to'be accurately and securely positioned in one of said bores and having a cylinder therein and having means thereon adapted to be engaged by means on said housing for securing said sleeve against axial movement in said housing, a pumping piston in said cylinder, a plug threadably engaging said sleeve and adapted to abut against said housing, said plug having a passage extending therethrough, and anoutlet check valve in said cartridge whereby fluid pumped by said piston is diverted from said common discharge passage by said sleeve and discharged through said' passagein saidplug.

12. A multiple piston hydraulic pump having a housing defining" apl'urality of circumferentially spaced bores and a common outlet communicable with said bores; an aerating cartridge assembly comprising; a sleeve adapted to be inserted said housing ffofii the outsidethef'iif aiid be accurately and s'eeiirely positioned in at least one of said bites andhaving a cylinder therein, and having means thereon adapted to be engaged by meansor'isaid housing for securing said sleeve agaifistax ale/"estate said housing, said sleeve being iriipeffdrat so as to block flow from its piston is said common gil'itlet, a pumping piston in said cylinder; a plug threadael y figaig trig said sleeve and Having means for fiiie'tin to a cdriduitf, said plug also having a} passage iitnding th a through, and an diitle'fi check valve said s'leie'bt-W at said cylinder and said passa e whereby filfideni es by sate piston is diverted through said sleeve and discharged through said passage in said plug'l References Gitd in the file of this patent UNITED STATES PATENTS 18 513 ebda a1 1J. e.. 868 197 06 R be v- 23 2 2,344,555 Scott et al' Mar. 21, 1;9 4 4 F 2 .9. 5. 2,381,585 Gambrell dudu 7 1945 2,3 9,374; Levy Nov. 20, 19415 2 ,395 ,9 4 Eodor Mar. 5;, 945

2 4582% Pa r a 4 12.4 t 0 9 Mansea t 9 9 1 zgmn i, shield M 1- .5 2,715,815 Tow ler Aug. 23,- 1 955 2,732,805 Lucien Jan. 31, 1956 V V FOREIGN PATENTS 1 4-31057 Australia Au 24', 193511 646,371 Great'Britain Nov. 22, I950 MW-gm 

